The title “Pineapple Express” refers to one plot element that turns out to be perhaps the movie’s most influential character: an especially potent kind of marijuana. It’s Pineapple Express that Saul Silver (James Franco) sells to Dale Denton (Seth Rogen), a sample that only Silver has. And it’s Pineapple Express that Dale is smoking when he witnesses a murder. And it’s due to drug cartels warring over Pineapple Express that that murder takes place. Now the killers, played by Gary Cole and the Puerto Rican actress Rosie Perez, spot the Pineapple Express that Dale dropped when he fled in terror, and they set out to kill Saul and his customer.

“Pineapple Express,” the movie, is an unexpected and interesting combination of three different genres, only one of which comes across in the synopsis I just gave you. It’s a hilarious comedy; it’s a buddy picture, about two friends adventuring and bonding; and, as you can gather from the above paragraph, it’s a crime story that eventually becomes excessively violent. That may just be this movie’s biggest surprise: that a Judd Apatow-produced comedy with the usual cast and improvisational style – usually associated with comedies about boy-men growing up like “The 40-Year-Old Virgin,” “Knocked Up” and “Superbad” – suddenly climaxes in shootouts, explosions, dead bodies and tons of blood. But, jeez, they sure do make that violence funny.